Metagenomics reveals taxon-specific responses of soil nitrogen cycling under different fertilization regimes in heavy metal contaminated soil.

Soil deficiency, cyclic erosion, and heavy metal pollution have led to fertility loss and ecological function decline in mining areas. Fertilization is an important way to rapidly replenish soil nutrients, which have a major influence on the soil nitrogen cycling process, but different fertilization regimes have different impacts on soil properties and microbial functional potentials. Here, metagenomic sequencing was used to investigate the different responses of key functional genes of microbial nitrogen cycling to fertilization regimes and explore the potential effects of soil physicochemical properties on the key functional genes. The results indicated that AC-HH (ammonium chloride-high frequency and concentration) treatment significantly increased the gene abundance of norC (13.40-fold), nirK (5.46-fold), and napA (5.37-fold). U-HH (urea-high frequency and concentration) treatment significantly increased the gene abundance of hao (6.24-fold), pmoA-amoA (4.32-fold) norC (7.00-fold), nosZ (3.69-fold), and nirK (6.88-fold). Functional genes were distributed differently among the 10 dominant phyla. The nifH and nifK genes were distributed only in Proteobacteria. The hao gene was distributed in Gemmatimonadetes, Nitrospirae and Proteobacteria. Fertilization regimes caused changes in functional redundancy in soil, and nirK and nirB, which are involved in denitrification, were present in different genera. Fertilization regimes with high frequency and high concentration were more likely to increase the gene abundance at the genus level. In summary, this study provides insights into the taxon-specific response of soil nitrogen cycling under different fertilization regimes, where changes in fertilization regimes affect microbial nitrogen cycling by altering soil physicochemical properties in a complex dynamic environment.

Metagenomics combined with metabolomics reveals the effect of Enterobacter sp. inoculation on the rhizosphere microenvironment of Bidens pilosa L. in heavy metal contaminated soil.

Metagenomics analysis was performed to determine the effects of Enterobacter sp. FM-1 (FM-1) on key genera as well as functional genes in the rhizosphere of Bidens pilosa L. (B. pilosa L.). Moreover, metabolomics was used to reveal the differences among rhizosphere metabolites after FM-1 inoculation. FM-1 inoculation significantly increased the activity of enzymes associated with the carbon cycle in soil; among them, invertase activity increased by 5.52 units compared to a control. Specifically, the relative abundance of beneficial genera increased significantly, such as Lysobacter (0.45-2.58 unit increase) in low-contamination soils (LC) and Pseudomonas (31.17-45.99 unit increase) in high-contamination soils (HC). Comparison of different transformation processes of the C cycle revealed that inoculation of FM-1 increased the abundance of functional genes related to the carbon cycle in LC soil. In contrast, the nitrogen cycling pathway was significantly elevated in both the LC and HC soils. FM-1 inoculation reduced HM resistance gene abundance in the rhizosphere soil of B. pilosa L. in the LC soil. Moreover, FM-1 and B. pilosa L. interactions promoted the secretion of rhizosphere metabolites, in which lipids and amino acids played important roles in the phytoremediation process. Overall, we explored the rhizosphere effects induced by plantmicrobe interactions, providing new insights into the functional microbes and rhizosphere metabolites involved in phytoremediation.

Insight into the roles of soluble, loosely bound and tightly bound extracellular polymeric substances produced by Enterobacter sp. in the Cd2+ and Pb2+ biosorption process: Characterization and mechanism.

Extracellular polymeric substances (EPSs) are macromolecular polymers formed by metabolic secretion, and they have great potential for removing heavy metal (HM) ions from the aquatic phase. In this study, the contributions of soluble EPSs (S-EPSs), loosely bound EPSs (LB-EPSs) and tightly bound EPSs (TB-EPSs) secreted by Enterobacter sp. to Cd2+ and Pb2+ adsorption were analyzed. The results indicated that in a solution containing both Cd2+ and Pb2+, pH= 6.0 was best suited for the adsorption process, and adsorption equilibrium was reached in approximately 120 min. Moreover, the mechanism for adsorption of Cd2+ and Pb2+ by the different layers of EPSs involved spontaneous chemical processes. However, Cd2+ adsorption by the three layers of the EPSs was an exothermic process (∆H0 <0), but Pb2+ adsorption by the three layers of the EPSs was an endothermic process (∆H0 >0). The variations in zeta potentials indicated that ion exchange occurred during Cd2+ and Pb2+ adsorption. FT-IR, XPS and 3D-EEM analyses indicated that the functional groups of the EPSs involved in adsorption were mainly the CO, C-O and C-O-C groups of the polysaccharides; furthermore, fulvic acid-like substances, humic-like substances and tyrosine-like proteins played important roles in the adsorption of Cd2+ and Pb2+ by the different EPS layers.

Highly Fluorescent N-Doped Carbon Quantum Dots Derived from Bamboo Stems for Selective Detection of Fe3+ Ions in Biological Systems.

The establishment of sensing platform for trace analysis of Fe3+ in biological systems is meaningful for health monitoring. Herein, a Fe3+ sensitive fluorescent nanoprobe was constructed based on highly fluorescent N-doped carbon quantum dots (NCQDs) derived from bamboo stems through a hydrothermal method employing ethylenediamine as the nitrogen dopant. The prepared NCQDs had a uniformly distributed size and their mean size was around 2.43 nm. Abundant functional groups (C=N, N-H, C=O, and carboxyl) anchored on NCQDs demonstrated successful doping of N in CQDs. The obtained NCQDs possessed a high fluorescence quantum yield of 20.02% and outstanding fluorescence stability over a wide pH range and at high ionic strengths. Moreover, Fe3+ ions presented a specific fluorescent quenching effect to the as-prepared NCQDs. The calibration curve for fluorescence quenching degree corresponding to Fe3+ concentration showed a linear response in a range of 0.01-10 µM, and detection limit was 0.486 µM, which indicated that the NCQDs had high sensitivity to Fe3+ ions. Ascribed to these unique properties, the NCQDs were selected as luminescent probes for trace amount of Fe3+ ions in human serum. These results demonstrated their promising use in clinical diagnostics and other biologically relevant studies.

Prenatal diagnosis of skeletal dysplasias using whole exome sequencing in China.

BACKGROUND: Skeletal dysplasias account for nearly 10% of fetal structural malformations detected by ultrasonography. This clinically heterogeneous group of genetic anomaly includes at least 461 genetic skeletal disorders with extreme clinical, phenotypic, and genetic heterogeneities, thus, significantly complicates accurate diagnosis. Researches have used whole exome sequencing (WES) for prenatal molecular diagnoses of skeletal dysplasias, however, data are still limited. METHODS: DNA extracted from umbilical cord blood or amniocytes from fetuses suspected of skeletal dysplasias based on ultrasound evaluations were analyzed by WES. Blood samples were taken from the parents of the positive fetuses for co-segregation analysis using Sanger sequencing. RESULT: Definitive molecular diagnosis was made in 6/8 (75%) cases, comprised of 5 de novo disease-causing changes in 3 genes (FGFR3, COL2A1, and COL1A2) and one proband with a biallelic deficiency for Lamin B Receptor(LBR),and including 3 novel variants. All fetuses had no detectable copy number variation (CNV) from sequencing results. CONCLUSIONS: Our study suggests that WES is an efficient approach for prenatal diagnosis of fetuses suspected of skeletal abnormalities and contributes to parental genetics counseling and pregnancy management.

[Electroacupuncture at Zhongji (CV 3) for treatment of benign hyperplasia of prostate: a multi-central randomized controlled study].

OBJECTIVE: To assess the role of Zhongji (CV 3) in treatment of benign hyperplasia of prostate. METHODS: Multi-central, randomized, controlled, single bland clinical method was adopted, and 276 cases were divided into an electroacupuncture (EA) group and a medication group, 138 cases in each group. The EA group were treated with EA at Zhongji (CV 3) and the medication group with oral administration of Qianliekang tablets. After treatment of 1 course, their therapeutic effects and changes of international prostate symptom (I-PSS) cumulative score, life quality index (L) cumulative score, nocturia times, urine stream state, lower abdominal symptom, maximal volume of urine flow, residual urine volume, prostatic volume, etc. Were assessed in the two groups. RESULTS: The total effective rate was 96.4% in the EA group and 86.2% in the medication group, the former being better than the latter (P<0. 01); the two groups were effective in improvement of international prostate symptom (I-PSS) cumulative score, life quality index (L) cumulative score, nocturia times, urine stream state, hypogastrium symptom, maximal volume of urine flow, residual urine volume, prostatic volume, etc. with the former better than the latter. CONCLUSION: Acupuncture at Zhongji (CV 3) has a significant therapeutic effect for treatment of benign hyperplasia of prostate.

[Effects of needle knife relaxing therapy on tension of local soft tissue and pain of osteoarthritis of knee].

OBJECTIVE: To probe into the mechanism and methods of needle knife relaxing therapy for treatment of osteoarthritis of knee from biomechanical view. METHODS: Needle knife relaxing therapy was given to 92 pain points around the knee joint in 14 cases of osteoarthritis of knee, and the displacement of the local pain point under the stress of 500 g (L500 g) was measured and the VAS scores were recorded before and after treatment. RESULTS: L500 g of the pain point was (4.72+/-1.03) mm before treatment and (5.39+/-1.01) mm after treatment with a very significant difference before and after treatment (P<0.01), and VAS score was (7.10+/-1.49) points before treatment and (1.49+/-1.24) points after treatment with a very significant difference before and after treatment (P<0.01), and there was a linear correlation between the changes of L500 g and VAS scores. CONCLUSION: There was close connection between the local pain and tension of local soft tissue in knee osteoarthritis. The needle knife relaxing therapy can relieve the neurovascular compression or traction syndrome by relaxing the local contracted, adhesive soft tissue, so as to relieve tension pain and finally recover internal force equilibrium of the knee joint.